Biology subjects

Roelofs, J. J. T. H.

Publications and source records attributed to Roelofs, J. J. T. H..

4 recordsLinked to original sources

bioRxiv2023

Treatment with a selective histone deacetylase (HDAC) 1 and 2 inhibitor in aged mice rejuvenates multiple organ systems

The process of aging increases the risk of developing age-related diseases, which come at great societal healthcare costs and suffering to individuals. Meanwhile, targeting the basic mechanisms of aging can reduce the risk of developing age-related diseases during aging, essentially resulting in a healthy aging process. Multiple aging pathways exist, which over past decades have systematically been confirmed through gene knockout or overexpression studies in mammals and the ability to increase healthy lifespan. In this work, we perform transcriptome-based drug screening to identify small molecules that mimic the transcriptional profiles of long-lived genetic interventions in mammals. We identify one small molecule whose transcriptional effects mimic diverse known genetic longevity interventions: compound 60 (Cmpd60), which is a selective inhibitor of histone deacetylase 1 (HDAC1) and 2 (HDAC2). In line with this, in a battery of molecular, phenotypic, and bioinformatic analyses, in multiple disease cell and animal models, we find that Cmpd60 treatment rejuvenates multiple organ systems. These included the kidney, brain, and heart. In renal aging, Cmpd60 reduced partial epithelial-mesenchymal transition (EMT) in vitro and decreased fibrosis in vivo. For the aging brain, Cmpd60 reduced dementia-related gene expression in vivo, effects that were recapitulated when treating the APPSWE-1349 Alzheimer mouse. In cardiac aging, Cmpd60 treatment activated favorable developmental gene expression in vivo and in line with this, improved ventricular cardiomyocyte contraction and relaxation in a cell model of cardiac hypertrophy. Our work establishes that a systemic, two-week treatment with an HDAC1/2 inhibitor serves as a multi-tissue, healthy aging intervention in mammals. This holds potential for translation towards therapeutics that promote healthy aging in humans.

pathology↗

bioRxiv2023

Air Pollution Aggravates Renal Ischemia-Reperfusion-Induced Acute Kidney Injury

Chronic kidney disease (CKD) has emerged as a significant global public health concern. Recent epidemiological studies have highlighted the link between exposure to fine particulate matter (PM2.5) and declined renal function. PM2.5 exerts its harmful effects on various organs through oxidative stress and inflammation. Acute kidney injury (AKI) resulting from ischemia reperfusion injury (IRI) involves similar biological processes involved in PM2.5 toxicity and is a known risk factor for CKD. The objective of this study was to investigate the impact of PM2.5 exposure on IRI-induced AKI. Mice were exposed to PM2.5 or filtered air for 12 weeks before IRI, and were euthanized 48h after IRI. Animals exposed to PM2.5 and IRI exhibited reduced glomerular filtration and impaired urine concentration ability. Moreover, they showed elevated tubular damage markers NGAL and KIM-1, along with significant tubular necrosis. PM2.5 exposure exacerbated local innate immune activation, leading to an increased infiltration of Ly6G+ granulocytes and F480+ macrophages in the kidney. This, in turn, contributed to heightened renal senescence markers and myofibroblast infiltration. Collectively, our findings suggest that AKI-induced hampered tubular function is worsened by PM2.5, leading to reduced resilience to stress, activation of aging mechanisms and early hallmarks of fibrosis. Decreasing PM2.5 and implementing preventive strategies can improve AKI patients outcome and prevent AKI progression.

pathology↗

bioRxiv2022

Endothelial transmigration hotspots limit vascular leakage through heterogeneous expression of ICAM1

Upon inflammation, leukocytes leave the circulation by crossing the endothelial monolayer at specific transmigration hotspot regions. Although these regions support leukocyte transmigration, their functionality is not clear. We found that endothelial hotspots function to limit vascular leakage during transmigration events. Using the photo-convertible probe mEos4b, we traced back and identified original endothelial transmigration hotspots. Using this method, we show that the heterogeneous distribution of ICAM-1 determines the location of the transmigration hotspot. Interestingly, loss of ICAM-1 heterogeneity either by CRISPR/Cas9-induced knockout of ICAM-1 or equalizing the distribution of ICAM-1 in all endothelial cells results in loss of TEM hotspots but not necessarily in reduced TEM events. Functionally, loss of endothelial hotspots results in increased vascular leakage during TEM. Mechanistically, we demonstrate that the 3 extracellular Ig-like domains of ICAM-1 are crucial for hotspot recognition. However, the intracellular tail of ICAM-1 and the 4th Ig-like dimerization domain are not involved, indicating that intracellular signalling or ICAM-1 dimerization is not required for hotspot recognition. Together, we discovered that hotspots function to limit vascular leakage during inflammation-induced extravasation.

immunology↗

bioRxiv2019

Dual role of protease activated receptor 4 in acute kidney injury: contributing to renal injury and inflammation, while maintaining the renal filtration barrier upon acute renal ischemia reperfusion injury

Ischemia reperfusion (I/R) injury triggers the activation of coagulation and inflammation processes involved in the pathophysiology of acute kidney injury (AKI). Coagulation proteases upregulated upon renal I/R injury activate protease activated receptors (PARs), which form an important molecular link between inflammation and coagulation. PAR4 is the major thrombin receptor on mouse platelets, and the only PAR that is expressed on both human and murine platelets. In addition, PAR4 is expressed on other cells including podocytes. We here sought to determine the contribution of PAR4 in the host response to renal I/R injury. Hence, we subjected PAR4 knockout and wild-type mice to renal I/R injury. PAR4 knockout mice exhibited an increased tolerance to renal tubular necrosis and showed a decreased neutrophil influx in response to renal I/R, independent from platelet PAR4. On the other hand, PAR4 deficiency resulted in albumin cast formation in peritubular capillaries and showed a tendency towards albuminuria. Transmission Electron Microscopy revealed an increase in podocyte foot process effacement. Our findings suggest that PAR4 contributes to renal injury likely through facilitating neutrophil migration, independent from platelet PAR4. In addition, PAR4 fulfils an important function in the maintenance of podocyte integrity following renal I/R insult. Subsequently, loss of PAR4 results in albuminuria.

immunology↗